package com.sinba.itsm.web;

import ognl.DefaultTypeConverter;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.time.DateUtils;

import org.apache.log4j.Logger;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;

public class DateConverter
    extends DefaultTypeConverter
{
    private static final Logger logger = Logger.getLogger( DateConverter.class );
    private static final String DATETIME_PATTERN = "yyyy-MM-dd HH:mm:ss";
    private static final String DATETIME_HOURS = "yyyy-MM-dd HH:mm";
    private static final String DATE_PATTERN = "yyyy-MM-dd";
    private static final String MONTH_PATTERN = "yyyy-MM";

    /**
     * Convert value between types
     */
    @SuppressWarnings( "unchecked" )
    public Object convertValue( Map ognlContext, Object value, Class toType )
    {
        Object result = null;

        if ( toType == Date.class )
        {
            try
            {
                result = doConvertToDate( value );
            } catch ( ParseException e )
            {
                // TODO Auto-generated catch block
                logger.error( "Converting from milliseconds to Date fails!" );

//						e.printStackTrace();
            }
        } else if ( toType == String.class )
        {
            result = doConvertToString( value );
        }

        return result;
    }

    /**
     * Convert String to Date
     *
     * @param value
     * @return
    * @throws ParseException
     */
    private Date doConvertToDate( Object value )
                          throws ParseException
    {
        Date result = null;

        if ( value instanceof String )
        {
            result =
                DateUtils.parseDate( (String) value,
                                     new String[] { DATE_PATTERN, DATETIME_PATTERN, MONTH_PATTERN, DATETIME_HOURS } );

            // all patterns failed, try a milliseconds constructor
            if ( ( result == null ) && StringUtils.isNotEmpty( (String) value ) )
            {
                try
                {
                    result = new Date( new Long( (String) value ).longValue(  ) );
                } catch ( Exception e )
                {
                    logger.error( "Converting from milliseconds to Date fails!" );

                    //e.printStackTrace();
                }
            }
        } else if ( value instanceof Object[] )
        {
            // let's try to convert the first element only
            Object[] array = (Object[]) value;

            if ( ( array != null ) && ( array.length >= 1 ) )
            {
                value = array[0];
                result = doConvertToDate( value );
            }
        } else if ( Date.class.isAssignableFrom( value.getClass(  ) ) )
        {
            result = (Date) value;
        }

        return result;
    }

    /**
     * Convert Date to String
     *
     * @param value
     * @return
     */
    private String doConvertToString( Object value )
    {
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat( DATETIME_PATTERN );
        String result = null;

        if ( value instanceof Date )
        {
            result = simpleDateFormat.format( value );
        }

        return result;
    }
}
